But diplomatic observers in Washington said that Mr Karzai’s remarks were part of his strategy to distance himself from the Americans who plan to withdraw most of their troops from Afghanistan by 2014. This did not reflect a serious rupture between Washington and Kabul, they said.

Mr Kerry is likely to discuss the future political set-up in Afghanistan as Mr Karzai completes his second and final term next year and steps down after holding general elections.

The United States and its Nato allies have promised to stay engaged with Afghanistan after 2014 as well, pledging to continue their economic assistance to the war-ravaged country.